Monster frequency
The term monster frequency refers to a number which can technically range 0-7 (though 6 and 7 are not used) used internally to determine how frequently a monster is generated; it can be thought of as a relative probability that a particular monster will be selected.
When a monster is randomly being selected, the game will tally all of the monsters with a difficulty from one-sixth that of the current level's difficulty to the average of the level's difficulty of the player level[1], sum their frequencies[2], generate a random number, and subtract the frequencies of successive monsters from this random number until zero is reached - the current monster is then selected[3].
When a monster is randomly being selected, the game picks a random monster subject to the following list of conditions with relative probabilities equal to the ratios of numberic monster frequencies (thus a monster with a 4 is twice as common as a monster with a 2).
Randomly generated monsters must be:
- No greater in difficulty than the average of the level's difficulty and the player level [4]
- No lower in difficulty than one-sixth that of the current level's difficulty
- Represented by an upper case letter, if you are on the rogue level [5]
- Neither unique or marked as not randomly generated (G_NOGEN) [6]
- Not genocided or extinct
- Not Lawful, if you are in Gehennom
- Not marked as only generated in Gehennom (G_HELL) (e.g. hell hound) while you are not in Gehennom
- Not marked as not generated in Gehennom (G_NOHELL) (e.g. winter wolf) while you are in Gehennom
Before monster frequencies are used for generation, a number is added to them depending on the relationship between the monster's alignment and the dungeon or special level's alignment. [7]
References
- This page is a stub. Should you wish to do so, you can contribute by expanding this page.
A user has suggested improving this page or section as follows:
"Terms for the probability numbers need to be defined!"